1. Field of the Invention
The present invention relates to a threaded connection piece, for a sensor.
2. Description of Related Art
A sensor for the combined measurement of pressure and temperature is known from published German patent application document DE 10 2006 043 324 A1, which has a threaded connection piece that is able to be screwed into an accommodating opening of a component, such as an accommodating opening in a fluid line of an air conditioning system. For this purpose, the threaded connection piece has a cylindrical base element, that is able to be introduced at least partially into the accommodating opening, and that is provided with a threaded section. When the threaded connection piece is screwed into the accommodating opening, that is provided with an inner thread, the base element comes into contact with a sealing surface, that is developed in the form of an end-face sealing cone, at a shoulder developed in the accommodating opening, while developing a sealing seat, whereby the accommodating opening is sealed. The threaded connection piece may be produced, for instance, using a metal injection molding method, as an MIM component (metal injection molding), or also as a turned part, or in another form.
Such threaded connection pieces are installed in air conditioning systems of motor vehicles, for example, for combined pressure and temperature sensors. In the case of CO2 air conditioning systems, there are very high requirements on sealing. Thus, the leakage may not be greater than 1 g of CO2 per annum. The threaded connection piece has to be able to be screwed into the accommodating opening repeatedly, without loss of sealing effectiveness, and is screwed into a relatively soft component made of aluminum using a relatively small screw-in torque of about 10 Nm. The media temperatures, that occur during the operation of the air conditioning system, of −40° C. to 180°, condition great differences in the longitudinal extension of the threaded connection piece and the accommodating opening, whereby the sealing effect may be reduced. In an unfavorable case, the connection between the threaded connection piece and the accommodating opening becomes leaky. As the distance between the threaded section of the threaded connection piece and the sealing cone of the threaded connection piece becomes greater, the danger of leakiness increases.